1. Field of the Invention
The present invention relates to an air bag device attached to an instrument panel, a steering wheel or the like of a vehicle.
2. Description of the Related Art
In recent years, an air bag device has been proposed as a device for protecting a vehicle occupant in an emergency.
This air bag device is designed to protect the occupant in such a way that an air bag body for the air bag device is filled with gas during a sudden deceleration of the vehicle, thereby expanding the air bag body in front of or toward the side of the occupant.
FIG. 16 shows one example of the air bag device. Inside an air bag body 70 a strap 72 is provided which can be broken by a tensile force larger than a predetermined value (Japanese Utility Model Application Laid-Open No. 1-125753). One end 72A of the strap 72 is attached to the occupant side 70A of the air bag body 70 via a plate 74. The other end 72B thereof is secured by bolts or the like to a case 76 which contains the air bag body. Accordingly, when the air bag body 70 is inflated, the strap 72 blocks the inflation of the air bag body 70 toward the occupant. As shown in FIG. 16, this directs the inflation of the air bag body 70 perpendicular to the direction of the occupant (in the direction of an arrow A in FIG. 16.) Pressure inside the air bag body 70 is then increased until the tensile force applied to the strap 72 reaches the predetermined value. The strap 72 then breaks so as to inflate the air bag body 70 in a desired direction (for example, in an upward direction of the vehicle), as illustrated in FIG. 17.
However, in this air bag device, there is no specific means for finally forming the air bag body 70 into a desired inflation shape after the strap 72 is broken. This causes an inconvenience in that it is difficult to provide a desirable final inflation shape of the air bag body 70.